2014 Breeding and Management Recommendations and Summary of the Status of the Giant Panda Ex Situ Population
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Report to: Chinese Association of Zoological Gardens (CAZG) Giant Panda Office, Department of Wildlife Conservation, State Forestry Administration Giant Panda Conservation Foundation (GPCF) 2014 Breeding and Management Recommendations and Summary of the Status of the Giant Panda Ex Situ Population 7 - 9 November 2013 Chengdu, China Submitted by: Kathy Traylor-Holzer, Ph.D. Jonathan D. Ballou, Ph.D. IUCN/SSC Conservation Breeding Specialist Group Chinese translation provided by: Yan Ping Sponsored by: Smithsonian Conservation Biology Institute Executive Summary This is a report on the meeting held 7 - 9 November 2013 in Chengdu, China to update the analysis of the ex situ population of giant pandas and develop breeding recommendations for the 2014 breeding season. This is the 12th annual set of genetic management recommendations developed for giant pandas. The current ex situ population of giant pandas consists of 375 animals (169 males, 205 females, 1 unsexed panda) located in 72 institutions worldwide. In 2013 there were 49 births and 13 deaths. The genetic status of the population is currently healthy, with 52 founders represented and another 14 that could be genetically represented if they were to successfully breed. There are only 3 inbred animals with inbreeding coefficients > 3% in the population. There are 50 giant pandas in the studbook that are living or have living descendents and for which the sire is uncertain. Most of these are pandas that were born in 2006 or later and are the result of natural mating and/or artificial insemination with multiple males. The result is that 10% of the gene pool of the ex situ population is derived from uncertain ancestry. Molecular genetic analyses must continue to be used to confirm the parentage of these pandas as well as each year’s new cubs before the next set of genetic management recommendations is made. This report contains the list of giant pandas that need to have their paternity verified (see page 13). Plans should continue to resolve as many of these uncertainties within the next year as possible. Population growth in 2013 was 10%, which is close to the average growth rate for the past eight years. Growth focused on breeding genetically valuable animals as part of the genetic management strategy to preserve genetic diversity and minimize inbreeding, with some additional breeding targeting production of pandas for eventual potential release. The current population goal for the giant panda ex situ population is to maintain a target population of 400-600 giant pandas that retains at least 90% gene diversity of the wild population for 200 years. A population of this size and genetic composition should be able to provide animals for reintroduction efforts if needed in the future. 2014 Genetic Management – Page 1 Table of Contents Section: Page Ex Situ Giant Panda Management Program 3 Status of Captive Population Data analysis and pedigree assumptions 4 Demographic status 5 Genetic status 6 2014 Breeding Recommendations 7 APPENDIX A: Assumptions about breeding population for analysis 10 APPENDIX B: Giant pandas with uncertain paternity 12 APPENDIX C: Ranked mean kinship (MK) list for giant panda captive population 15 APPENDIX D: Giant panda MSI values for mate selection during the 2014 breeding season (distributed November 2013) 20 MSI Tables 22 2014 Genetic Management – Page 2 Ex Situ Giant Panda Management Program Introduction This is a report on the meeting held 7 - 9 November 2013 in Chengdu, China to update the analysis and breeding plan of the ex situ population of giant pandas. Workshop participants updated the studbook and identified the females to be bred in 2014 and the males with which they should breed. The meeting was organized by the Chinese Association of Zoological Gardens (CAZG) and the Chengdu Research Base for Giant Panda Breeding, and technical workshop was facilitated by the IUCN SSC Conservation Breeding Specialist Group (CBSG). The goals of the technical workshop were to: update the studbook with reports from all participating institutions; update the demographic and genetic analyses of the ex situ population; and formulate recommendations for breeding and management to promote these goals. Population Goals In 2009 the Technical Committee revised the program goal to maintain at least 90% gene diversity for 200 years with a target population size of approximately 500 (400-600) giant pandas. A longer timeline was adopted due to the uncertainty surrounding the possible significant threats of climate change and habitat destruction. The rate of growth toward this new target size can be slowed, and increased effort will be placed in genetic management and natural reproductive and parental behaviors. Genetic management is the most effective method of maintaining a genetically viable ex situ population capable of supporting a wild panda population. The current population of 375 giant pandas needs to increase by 125 to reach the goal of 500 pandas (Figure 1). 600 Target Population Size = ~500 500 400 N= 375 300 # Giant # Pandas 200 100 0 2000 2002 2004 2006 2008 2010 2012 Year Figure 1. Growth of the ex situ giant panda population from 2000 to 2013. 2014 Genetic Management – Page 3 Status of Captive Population Data Analysis and Pedigree Assumptions Data were taken from the 8 November 2013 version of the International Giant Panda Studbook compiled by Xie Zhong, CAZG, using the ISIS Single Population Analysis and Record Keeping System (SPARKS) v1.66 software program. An analytical studbook (see below) was created in SPARKS v1.66, and PMx v1.2 software (Ballou, Lacy and Pollak) was used to conduct both demographic and genetic analyses. Data were current through the day of the workshop, as the studbook was updated during the workshop by institutional representatives. Paternity is uncertain for many animals in the studbook. For many of these cases, females were first mated naturally and were then artificially inseminated. In others, lack of record-keeping in the early studbook years resulted in uncertainty about which males sired which cubs. Although molecular analyses have successfully identified the paternity of many pandas, there are still 50 pandas with uncertain paternity that affect the living gene pool, many of which were born between 2006 and 2013 (listed in Appendix B). The uncertain paternity of these individuals results in 10% of the living gene pool being uncertain. SPARKS v1.66 provides the option to list the studbook numbers of the potential sires along with the probability of each of them being the real sire. These uncertain sires can then be exported to PMx, where the pedigree analysis will take into consideration the uncertainties and calculate the kinships based on the estimated paternity across the uncertain sires (see Lacy et al. 2011 for the methods). While the ability to include such uncertainty in the analyses are useful, and even necessary to proceed with developing breeding recommendations, the genetic analyses for this ex situ population will not be completely accurate until the paternities are known for certain through molecular genetic analyses. Molecular analyses are needed to resolve the paternity of these 50 pandas as soon as possible since genetic management recommendations will not be accurate with these unknowns in the pedigree. 2014 Genetic Management – Page 4 Demographic Status The current ex situ population of giant pandas consists of 375 animals (169 males, 205 females, 1 unsexed panda) located in 72 institutions worldwide. In 2013 there were 49 births and 13 deaths. Reproduction over the last several years has resulted in an annual population increase of 9-15% for 2005 to 2010. The growth rates were lower in 2011 (5%) and 2012 (3%) – presumably due to the increased focus on producing genetically valuable animals rather than large numbers. The growth rate now is being increased to accommodate the needs of a developing release and reintroduction program, and 10% growth was observed in 2013. The age structure of the living population is healthy and indicative of a population that would be expected to continue to grow (Figure 2). A greater proportion of adult pandas have reproduced, especially females (from 41% in 2002 to 45% in 2013), which contributes positively to growth as well as the effective population size (Ne). Females are generally reproductive from 5-20 years of age, while male fertility can continue into the 20s. Generation time for the population is 11 years. Litters consist of 1-2 cubs with almost equal frequency (four litters of triplets have been observed), producing a mean litter size of 1.5 cubs. About 50% of males survive to age 15, 25% survive to age 22, and only about 10% survive to age 28; female survivorship is slightly better, with about 50% reaching age 19, 25% surviving to age 28, and 10% surviving to age 34. These values include wild-caught pandas whose ages are estimated. Figure 2. Age and sex structure of the 2013 population. Dark blue are breeding age individuals; light blue are immature (at bottom) or post-reproductive (at top) pandas; yellow is the unsexed individual. 2014 Genetic Management – Page 5 Genetic Status The ex situ giant panda population has descended from 52 wild-acquired founders (founders are defined as animals obtained from the wild that have successfully produced offspring or descendants in the current population). There are an additional 14 wild-acquired pandas that have yet to produce living offspring but have not been excluded due to age or poor health (these are potential founders). The population theoretically contains 97.4% of the genetic diversity of the wild population. This level of genetic diversity has a founder genome equivalent (FGE) of 19.5, which means that the population has the same level of genetic diversity as a population newly established with 19 unrelated founders. The genetic contribution of founders is highly skewed, with 25% of the gene pool derived from only 4 founders (Figure 3).